Nortel BCM50 Configuration Manual page 308

308 Chapter 32 Private networking: MCDN over PRI and VoIP
Figure 98 MCDN networking, with a common public network connection
BCM
West-End branch
PNI= 1
Voice mail or
Auto Attendant
This example could represent a large head office (the Meridian 1) connected to several smaller
branch offices (the two BCMs). In this network, only the head office has trunks connected to the
public network.
The branch offices access the public network through the PRI to the head office. This
configuration allows for cost savings by consolidating the public access trunks. Users at all three
locations access the public network by dialing 9, followed by the public number. For example, a
user in the West End branch might dial 9-555-1212 (for a local call) or 9-1-613-555-1212 (for a
long-distance call). The BCM routing table routes these public calls to the Meridian 1. Routing
tables at the Meridian 1 will then select an appropriate public facility for the call.
Note that the Private Network Identifier (PNI) is programmed at each end of the links. The PNI
identifies the BCM to the Meridian 1 system.
Routing is set up such that network calls are made by dialing a four-digit private network DN. For
example, if a user in the West End branch wishes to call a user in the East End branch within the
private network, they dial 6221.
The implications on the configuration on each node to access the PSTN through one network node:
• Each node must have the Private Network Access Code set to the value 9.
• Each node must have destination codes that match the Private Network Access Code plus
digits corresponding to calls terminating in the local PSTN. For example, if the Private
Network Access Code is 9, the node in Ottawa would require a destination code of 91613.
Similarly, Toronto would require the following destination code: 91416.
NN40020-603 NN40020-603
Network # 2221
Received # 2221
Internal # 2221
PRI (SL-1)
Meridian M1
PRI (public protocol)
Central
Office
Figure 98
Network # 6221
Received # 6221
Internal # 6221
PRI (SL-1)
BCM
East-End branch
PNI=1
DN: 4221
illustrates this example.